This invention relates generally to carpet treatments, and in particular to a method for imparting repellency, stain-resistance and soil-resistance to carpets by applying to the carpet an aqueous treating solution comprising a fluorochemical and/or hydrocarbon agent, a stainblocking material, and a salt.
Various references describe methods for exhausting stainblocking materials, fluorochemicals, and/or waxes onto fibrous polyamide substrates to provide to the substrate good stain resistance to acid colorants and/or good water and oil repellency.
U.S. Pat. No. 4,875,901 (Payet et al.) discloses a method for providing fibrous polyamide substrates with stain resistance by contacting the substrate with an aqueous solution comprising a normally solid, water-soluble, partially sulfonated novolac resin and a water-soluble polyvalent metal salt.
U.S. Pat. No. 4,940,757 (Moss et al.) and its continuation-in-part, U.S. Pat. No. 5,310,828 (Williams et al.), describe polymeric compositions that impart stain resistance to polyamide fibers. The compositions are made by polymerizing an a-substituted acrylic acid or ester in the presence of a sulfonated aromatic formaldehyde condensation polymer. Optionally, this polymer can be combined with certain halogenated polymers such as perfluorinated urethanes and acrylates, and a small amount of a divalent metal salt, such as a magnesium salt, can be applied along with the stain resistant composition.
U.S. Pat. No. 4,822,373 (Olson et. al) describes treated fibrous polyamide substrates having applied thereto a partially sulfonated novolac resin and methacrylic acid-containing polymers.
U.S. Pat. No. 5,001,004 (Fitzgerald et al.) describes stain-resistant, polyamide textile substrates treated with compositions comprising hydrolyzed ethylenically unsaturated aromatic/maleic anhydride polymers. Optionally, a polyfluoroorganic oil-, water- and/or soil-repellent can be applied before, during, or after the application of the polymer. The hydrolyzed polymers can be applied to textile substrates in a variety of ways, e.g., during conventional beck and continuous dyeing processes, and are normally applied at an acidic pH.
World Published Patent Application WO 92/10605 (Pechhold) describes polyamide fibrous substrates having applied thereto (by padding, spraying, foaming, batch exhaust or continuous exhaust) a water-soluble or water-dispersible hydrolyzed or monoesterified alpha-olefin/maleic anhydride copolymer. Coapplication of a polyfluoroorganic oil-, water- and/or soil-repellent material is also disclosed.
World Patent Application No. WO 93/19238 (Pechhold) discloses a stain-resist which can be applied to polyamide textiles by padding or spraying comprising blends of maleic anhydride/alpha-olefin polymers with sulfonated phenol-formaldehyde condensation products. Optionally, a polyfluoroorganic oil-water- and/or soil-repellent can be applied before, during, or after the application of the polymer.
U.S. Pat. No. 4,925,707 (Vinod) describes the coapplication of fluorochemical anti-soilants with stainblockers to nylon carpet which is installed.
U.S. Pat. No. 5,252,232 (Vinod) describes an improved process for preparing a freeze-thaw stable aqueous composition comprising an aqueous perfluoroalkyl ester of citric acid and a hydrolyzed styrene/maleic anhydride copolymer which, when applied to an installed nylon carpet in such a way to thoroughly wet the pile fibers, imparts stain and soil resistance.
U.S. Pat. No. 5,073,442 (Knowlton et al.) describes a method for enhancing the soil- and/or stain-resistant characteristics of polyamide and wool fabrics by applying an aqueous solution containing various combinations of sulfonated phenolic compounds, compounds of sulfonated phenolics and aldehydes, fluorochemicals, modified wax emulsions, acrylics, and organic acids of low molecular weight.
U.S. Pat. No. 5,520,962 (Jones) describes a method and composition for treating carpet yarn to enhance its repellency and stain resistance by treating by immersion in an acidic aqueous medium containing an anionic or nonionic fluorochemical, heating, and removing the excess water.
U.S. Pat. No. 5,084,306 (McClellan et al.) discloses a flex nip process for coating carpets with an aqueous emulsion containing fluorochemical and polyvalent ions and/or acidifying agents.
U.S. Pat. No. 4,680,212 (Blyth et al.) describes undyed stain-resistant nylon fibers having coated on their surface one or more stainblockers and one or more fluorochemicals to impart stain resistance after trafficking. The coating is preferably applied to the nylon fibers as an aqueous spin finish during the melt spinning process used to prepare the fibers.
U.S. Pat. No. 5,516,337 (Nguyen) describes a method for improving stain resistance to fibers, especially wool, by (a) treating the fibers with a mordant, (b) treatment with a combination of sulfonated or disulfonated surfactant together with a stain resist chemical, and (c) providing treatment with a fluorochemical in either step (a) or (b) in an amount sufficient to improve stain resist properties.
European published application EP-A-797699 describes an aqueous treating composition for providing stain release properties to fibrous materials comprising (a) polymethacrylic acid [homopolymers] or copolymers containing methacrylic acid, (b) a partially sulfonated novolak resin, (c) a sulfated surfactant and (d) water, which can also contain divalent metal salts and can be coapplied with a fluorochemical composition.
U.S. Pat. No. 4,839,212 (Blyth et al.) describes nylon fibers coated with a sulfonated condensation product stainblocker and optional fluorochemical.
U.S. Pat. No. 4,959,248 (Oxenrider et al.) describes a process for imparting stain resisting properties to fibers formed from thermoplastic polymers by treating the fibers with a combination of a phenol condensation stainblocker and a fluorochemical anti-soiling agent made by reacting pyromellitic anhydride with fluorinated alcohol and an oxirane.
European Patent Application 0 353 080 (Ingham et al.) describes a process for improving the stain resistance of polyamide and keratinous fibers by treating the fibers in an aqueous dye bath at a long liquor ratio firstly with a fluorochemical composition and subsequently with a stainblocker. The reference states that the applicants found that simultaneous application results in interference between the fluorocarbon and the stainblocker.
Various fatty derivatives have been described as useful repellent and antisoiling treatments for fibrous substrates.
U.S. Pat. No. 2,876,140 (Sheehan) describes softening agents for textile materials having improved soil resistance which are a combination of barium sulfate and cationic softening agents. These softening agents are of the higher fatty acid amide type, such as the reaction products of polybasic organic acids with dialkylol substituted carbamido compounds carrying side chains containing polyamino acid radicals and their salts.
U.S. Pat. No. 4,076,631 (Caruso et al.) describes treating compositions for textiles to provide an antistatic, dirt repellent finish consisting essentially of (1) a fatty amide antistatic agent, (2) an aqueous dispersion of hard particles, such as polystyrene, polymethyl methacrylate or colloidal hydrous metal oxide, (3) a fluorine-free inorganic or organic monobasic or polybasic acid, (4) an antimicrobial agent, and (5) a fluorocarbon agent which provides a low free surface energy. At column 4, lines 37-50, treating of carpet to provide an antistatic character and resistance to dry soil (but not oily dirt) is described, though the method of treatment is not detailed
U.S. Pat. No. 4,144,026 (Keller et al.) describes a process for simultaneously providing textile materials with an antistatic and dirt-repellent finish by treating the textile materials with an aqueous solution containing (a) a copolymer of an xcex1,xcex2-unsaturated dicarboxylic acid or the anhydride thereof and at least one other ethylenically unsaturated compound, and (b) a fatty acid/alkanolamine reaction product or an alkylene oxide adduct of this reaction product, and subsequently drying them.
U.S. Pat. No. 4,153,561 (Hxc3xcmxc3xcller et al.) describes storage-stable aqueous emulsions for the treatment of textiles which contain salts of N-alkyl-xcex1-sulfosuccinic acid amides, fatty acid amide sulfates or glycerin ether derivatives, polyethylene glycols and non-ionic dispersing agents. These emulsions can be applied to carpets of synthetic fibers in continuous pad-dyeing or printing processes, giving good wetting, and upon drying provide a soft feel and anti-soiling to the fibers.
U.S. Pat. No. 4,329,390 (Danner) describes aqueous dispersions of a microcrystalline wax, optionally together with one or more non-oxidized paraffins, having a cationic surfactant used as a dispersing agent. These aqueous dispersions, when applied to textile substrates such as carpet via impregnation or exhaust processes, provide a textile substrate with improved sewability and less damage by high-speed sewing machines.
U.S. Pat. No. 4,883,188 (Kortmann et al.) describes stable aqueous waterproofing and oil-proofing finishing agents for textiles, especially nonwoven fabrics, containing (a) compounds containing a perfluoroalkyl group (preferably acrylate (co)polymers), and (b) quaternization products of basic fatty acid amides.
U.S. Pat. No. 5,491,004 (Mudge et al) describes a method for applying a low soil finish to spun synthetic textile fibers by applying a dry, way solid component comprising a fatty bisamide, a block copolymer of ethylene oxide and propylene oxide, the reaction product of a saturated fatty alcohol, a saturated fatty amine or an ethoxylated phenol, and/or a fatty acid ester.
None of the treating compositions and methods described in the art imparts to a fibrous substrate a simultaneous combination of exceptional dynamic water and oil repellency, in-depth stain resistance, and excellent durable anti-soiling performance. These and other advantages are provided by the present invention, as hereinafter described.
In one aspect, the present invention relates to a treatment for carpets and other fibrous substrates which imparts to the substrate exceptional dynamic water and oil repellency, in-depth stain resistance, and excellent durable anti-soiling performance. In accordance with the invention, the substrate is treated with a (typically aqueous) mixture comprising (1) a repellent material selected from the group consisting of glassy fluorochemicals having a receding contact angle to n-hexadecane of greater than 53xc2x0 (preferably, 65xc2x0 or higher, and more preferably, at least 70xc2x0 or higher) and glassy hydrocarbons having a receding contact angle to n-hexadecane of 35xc2x0 or higher; (2) a stainblocking material; and (3) an exhausting aid selected from the group consisting of metal salts and acids. The aqueous mixture is typically applied by contacting the fibrous substrate with the treatment solution in such a way as to fully contact all fibers of the substrate with the solution. The wet treated substrate is then exposed to steam or other water-saturated atmosphere for a sufficient period of time, and at a sufficiently high temperature, to affix the treating materials onto the fibrous substrate. The wet treated substrate is then rinsed with water and dried in an oven at a high enough temperature to activate the materials.
In another aspect, the present invention relates to fibrous substrates treated in accordance with the method described above which exhibit excellent anti-soiling, anti-staining and repellency performance. The fibrous substrate, having had total penetration of the fluorochemical, hydrocarbon and stainblocking materials into and throughout each fiber, exhibits excellent dynamic water resistance (i.e., resistance to penetration by water-based drinks spilled from a height), greatly resists staining by aqueous acid staining agents such as red KOOL-AID(trademark) drink, prevents oil penetration into any portion of the fiber, and in the case of carpet offers significant protection again dry soiling when compared to untreated carpet as demonstrated by several cycles of xe2x80x9cwalk-onxe2x80x9d tests.
In another aspect, the present invention relates to a method for identifying hydrocarbon and fluorochemical materials which will exhibit good anti-soiling properties when applied to a fibrous substrate. Surprisingly, it has been found that a strong correlation exists between receding contact angle and anti-soiling properties for fluorochemical and hydrocarbon materials when they are used as carpet treatments. Consequently, receding contact angle measurements may be used to readily identify fluorochemical and hydrocarbon materials having particularly good anti-soiling properties, without having to conduct lengthy walk-on soiling tests. For the purposes of the present invention, fluorochemicals having a receding contact angle to n-hexadecane of at least about 53xc2x0, preferably greater than about 65xc2x0, and more preferably at least about 70xc2x0 are found to exhibit particularly good anti-soiling properties. Similarly, hydrocarbon materials having a receding contact angle to n-hexadecane of at least about 35xc2x0 are found to exhibit particularly good anti-soiling properties. When they are to be used as anti-soiling agents on carpets, it is preferred that the fluorochemical or hydrocarbon materials are hard, glassy, non-tacky, non-cationic materials having a glass transition temperature of from about 20xc2x0 C. to about 130xc2x0 C.
In a further aspect, the present invention relates to an immersion process for treating carpets and other fibrous substrates to improve, for example, their anti-soiling properties, wherein the treating solution comprises a material that contains both fluorochemical and hydrocarbon moieties. Substrates treated in accordance with the method exhibit excellent anti-soiling properties, but at generally greater fluorine efficiency than treatments using similar materials that lack hydrocarbon groups.
In yet another aspect, the present invention relates to an immersion process for treating carpets and other fibrous substrates to improve, for example, their anti-soiling properties, wherein the treating solution comprises a blend of fluorochemical and hydrocarbon materials. Substrates treated in accordance with the method exhibit excellent anti-soiling properties, but at generally greater fluorine efficiency than treatments using only fluorochemical materials.
In still another aspect, the present invention pertains to a method for treating carpets and other fibrous substrates with a composition comprising a hydrocarbon material and, preferably, a stainblocker. The hydrocarbon material preferably has a receding contact angle to n-hexadecane of at least about 35xc2x0. Surprisingly, substrates treated in accordance with the method are found to exhibit excellent anti-soiling properties, even when the treatment composition does not contain a fluorochemical.